As with previous SimCity titles, SimCity 4 places players in the role of a mayor (or several mayors), tasked with populating and developing tracts of lands into cities, while fulfilling the needs of fellow Sims that live in the cities. Cities are now located in regions that are divided into segments, each of which can be developed. The player has the option of starting the city in a segment of any of three area sizes, in real measurement the smallest has a length of 1 kilometer on a side, and the largest has a length of 4 kilometers on a side.[3] A large city is 16 km²; for comparison the New York borough of Manhattan measures about 90 km². The size of a region and its layout of segments can be changed in a bitmap file provided for each region.

Zoning and building size have been improved for SimCity 4. Agriculture is now a separate industrial zone-type, enabling for farms to grow regardless of high land-value, so long as there exists demand for agriculture and agricultural zones have been provided. Zones are now automatically aligned towards roads; streets are automatically created when zoning on large tracts of land. Buildings are now classified into several wealth levels, zone types, and building size stages, which are affected by the region's population and the city's condition. The game simulates urban decay and gentrification with buildings darkening accordingly. Buildings originally constructed for occupation by higher wealth tenants can now support lower wealth tenants in the event surrounding factors forces the current tenants to vacate the building; this allows certain buildings to remain in use despite lacking its initial occupants. Buildings and lots can now be constructed on slopes.

SimCity 4 can be used in conjunction with The Sims. Sims can be imported into a city for use in the My sim mode. City layouts created in SimCity 4 can be used as neighborhood templates in The Sims 2; the location of roads, trees, bridges, and map features such as rivers and hills are preserved in the importation.[4]

On September 22, 2003, Maxis released an expansion pack for SimCity 4 dubbed Rush Hour, which is also included in The SimCity Box. The expansion pack, among others, enhances the range of transportation facilities, as well as allowing the player to trace traffic flow, control vehicles and construct larger civic facilities, and introduces a new range of contemporary Europe-styled buildings.

While previous mainstream SimCity titles could be best described as mayordom, or "God" simulators, SimCity Societies is different, as foreshadowed by the previews and statements from the developers,[5] by being a 'social engineering simulator' rather than a city-building simulator. The game is notably the first SimCity title not developed by Maxis.

Public works and a tax system do not play a part in the basic game. Instead, players get daily income from workplaces in the city. However, a downloadable update includes gameplay modes where a daily tax is incurred based on the buildings within a city. Transportation networks have been simplified to dirt roads, paved roads, subways and bus stops. Players do not build zones, a key element of past SimCity games; instead, they have the ability to directly place individual buildings, something not seen in previous editions, and similar to Monte Cristo's game City Life. There are also six "social energies", called societal values, which allow players to learn about the characteristics of the citizens. The six societal values are productivity, prosperity, creativity, spirituality, authority, and knowledge.[6] The city will look, and act, in accordance with the energies the players choose. Players may focus on satisfying one, several, or all of these values. An improved version of the reward system introduced in SimCity 2000 has been included in the game.[7]

The game is "fully customizable" and allows the players to customize individual buildings, decorations, citizens, and game rules.[8] Prior to its release, when mentioning the depth to which the game will allow customization a Tilted Mill representative stated that those who were proficient in C# and XML will have easy access to every asset of the game and that basic tools would be provided for building editing.[9]

EA has announced the first expansion for SimCity Societies, which is also included in The SimCity Box. The new expansion, SimCity Societies: Destinations will focus on a new strategic scene in SimCity, this time tourism.[10]

The Sims Carnival is an online community and gaming experience from The Sims, that gives the user the chance to act as a game developer in a new series of games.[11]The SimCity Box features one game from this called SnapCity, which is a SimCity-lookalike strategy/arcade game.